..Subjects ingested less calcium during bed rest, and with artificial gravity, they also absorbed less calcium. With exercise, they excreted less calcium. To retain bone during bed rest, calcium intake needs to be maintained...

Fifty years of human space travel: implications for bone and calcium research

..05) effect of time for whole body total BMC and total hip and trochanter BMD. These data failed to demonstrate efficacy of this AG prescription to prevent the changes in bone metabolism observed during 3 wk of bed rest...

..Eight pairs of identical twins were randomly assigned to sedentary control or exercise groups. Exercise within LBNP decreased the bone resorption caused by bed rest and may provide a countermeasure for spaceflight...

..Bed rest is a valuable ground-based model for many of the physiological changes that are associated with spaceflight. Nutritional changes during and after 60 or 90 d of head-down bed rest were evaluated...

Sara R ZwartUniversities Space Research Association, Houston, Texas, United States of AmericaPLoS ONE 7:e31058. 2012

..In addition, folate status decreases quickly in this environment, and this study provides evidence that folate requirements may be greater when body iron stores and DNA damage repair responses are elevated...

A 250 μg/week dose of vitamin D was as effective as a 50 μg/d dose in healthy adults, but a regimen of four weekly followed by monthly doses of 1250 μg raised the risk of hypercalciuria

..Labile plasma iron was measurable only during the dive. These data indicate that the NEEMO environment increases body iron stores and labile forms of iron, which may contribute to oxidative damage...

..Based on prior observations of lengthening of the QTc interval during long-duration spaceflight, we hypothesized that abnormalities in ECG repolarization would also occur during long-duration HDBR...

..e. within days to weeks) suggests that alterations in bone metabolism are an early effect of weightlessness. These studies are important for a better understanding of bone metabolism in space crews and in those who are bedridden...

Calcium metabolism before, during, and after a 3-mo spaceflight: kinetic and biochemical changes

..The surge in life sciences research during this decade serves as a preamble to the opportunities to be provided by the latest addition to the Earth-orbiting structures--the International Space Station...

..This study provided the 1st set of spaceflight data for investigation of nutrient stability in the food system, and the results will help NASA design food systems for both ISS and space exploration missions...

Men and women in space: bone loss and kidney stone risk after long-duration spaceflight

..More complete knowledge of these processes can be expected to produce countermeasures that are even more successful, as well as expand our comprehension of the range of adaptability of human physiologic processes...